In the operation of two-cycle internal combustion engines it is important that an acceptable proportion of oil to gasoline be maintained. If too high a percentage of oil to gasoline is present the spark plugs are subject to fouling up and the pistons and valves are subject to undesirable carbon deposits whereupon the engine will not operate effeciently, and difficulties are encountered in starting the engine. If the percentage of oil to gasoline is too low there is a danger of the engine freezing up whereupon the pistons will not move within the cylinders.
Many attempts have heretofore been made to devise a readily workable system whereby the necessary quantity of oil can be added to gasoline to maintain the desired proportions oil to gasoline where additional fuel is added to a partially filled tank.